


The Closest of Sisters

by ForbiddenFlowerType_L



Category: BanG Dream! (Anime), BanG Dream! Girl's Band Party! (Video Game)
Genre: Consensual Underage Sex, Dead Dove: Do Not Eat, F/F, Fluff, Not Beta Read, Romance, Sibling Bonding, Sibling Incest, not much sex
Language: English
Status: Completed
Published: 2020-10-04
Updated: 2020-10-04
Packaged: 2021-03-08 02:47:52
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,847
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26808382
Author URL: https://archiveofourown.org/users/ForbiddenFlowerType_L/pseuds/ForbiddenFlowerType_L
Summary: Tomoe has always been closer to Ako than most older sisters are.
Relationships: Udagawa Ako/Udagawa Tomoe
Comments: 2
Kudos: 18





	The Closest of Sisters

Tomoe had always been close with her younger sister. Ako had looked up to her for as long as she could remember, and often tagged along when Tomoe went out to play or started practicing the drums.

Not that Tomoe minded – as far as she was concerned, she’d one the little sister lottery. Ako was cool, kind, a hard worker, an excellent drummer, fairly well behaved aside from occasionally staying up too late to play video games, cute, and an amazing cuddler. While the elder Udagawa knew many other older sisters who seemed to want nothing more than time away from their younger siblings, she had never related. Tomoe was always more than happy to spend her day together with Ako.

In fact, with Ako becoming a gamer and joining a band, Tomoe wanted nothing more than to spend  _more_ time with her. Ako seemed to agree, which had led to the return of some childhood habits of theirs like taking showers together before school or sharing a bed when they slept.

That still wasn’t quite enough for  the sisters, though, so they’d started a habit of going on ‘sister dates.’

Ako sat at a small table in a dimly lit cafe across from her older sister. The glow of a candle lit Tomoe’s objectively ultra-cool and pretty (in Ako’s opinion) face, along with two slices of cake. The one in front of the elder Udagawa was a chocolate cake recommended by Ako, while the one in front of the younger Udagawa was raspberry-chocolate, a flavor that she had wanted to try the last time she visited the cafe.

“You know, Ako, this cafe is very _you_ ,” said Tomoe, glancing at the dark purple fabric and black lace that decorated the room. 

“Right? I was super excited when Lisa-nee showed me this place. But if looks were the only good thing about it, I wouldn’t have chosen it as the site of something so important as one of our sister-dates. Try your cake, onee-chan!”

Tomoe did so.

“Wow, you’re right! This is a really amazing cake. I don’t think I’ve ever had one so… chocolatey before.”

“It’s amazing, right? Like the cake contains a portal to the Elemental Plane of Chocolate.”

“How’s your cake, Ako?”

  
“It’s really good! The sinful sweetness of the plain chocolate cake, balanced by the sourness of berries… truly, the devil himself would struggle to make a dessert with such a tempting balance.”

“Sounds tasty. Mind giving your older sister a bite?”

“Sure. Open your mouth, onee-chan.”

  
Ako carefully selected a spoonful of cake, and then guided it to Tomoe’s waiting mouth.

“That’s delicious. Uh, I know you already tried the regular chocolate cake the last time you came here, but do you want a bite in return?

“Yeah! Ahhh.”

That was the scene Moca walked in on when she entered the cafe to try out the Pain au Chocolat she’d heard rumors of.

“Oh, wow Tomo-chin. I knew that you were a siscon, but going on romantic candlelit dinners with Ako is next level,” the bread loving girl said with a sly grin on her face.

“Oh, hi Moca. Me and onee-chan are on a sister sate of, um, infernal bonding,” Ako explained innocently, not helping the situation at all.

“Oho, dating your own little sister, huh? That’s a bold choice,” said Moca.

“It’s not like that,” Tomoe protested, “It’s not a romantic date or anything. It’s just sisterly bonding time.”

“Really? So feeding each other cake and having indirect kisses is just perfectly normal sister stuff?”

The sisters blushed at the mention of kissing, but nonetheless, Ako replied, “ Have you never shared a water bottle with your family? And sisters feeding each other and going on dates is perfectly normal. I’ve seen Hina-senpai take Sayo-san on dates to Michelle Burger and feed her fries before.”

“I don’t think a fast food joint like Michelle Burger even counts as a date… but I guess you two would know what sister do better than I do,” Moca conceded, “Still, you two love each other a lot, don’t you?”

“Yes, I do,” said Tomoe without hesitation.

“I love onee-chan lots and lots too! She’s my most precious person,” added Ako, getting out of her chair to give her big sister a hug.

_____________________________________________________________________

Afterglow had decided to go on a trip to an onsen, and Tomoe had naturally asked if she could bring along her sister. The rest of Afterglow was used to this, and allowed it. Ako had been very happy for the invitation, too. And now, the sisters were washing each other in preperation to enter the outdoor bath.

“Onee-chan, have your boobs gotten bigger?” Ako asked giving her sister a soapy grope.

Tomoe ignored the shiver of pleasure that ran down her body. Those kinds of feelings didn’t count between sisters.

“Well, my bras _have_ felt kind of tight, recently. Maybe you can help me buy some new ones?”

“Yeah! I’ll make sure to balance your sexy-as-a-succubus-ness with your hot-as-hellfire-ness.”

“Sexiness and hotness are two different things?”

“Yeah, but they’re all connected. For example, the sexiness of your boobs is accentuated by the hotness of your abs.”

Ako ran a hand over those abs to underscore her point. Once again, Tomoe filed away the pleasure she felt as simple sisterly affection.

“Oh. I see. Well in that case, your cutie-patootie brings out your adorable smile,” Tomoe said while giving her younger sister’s bum a tick and eliciting a giggle from Ako.

“Jeeze, onee-chan, that’s completely different.”

Just then, Ran walked into the room.

“Are you guys done washing ye- what are you two doing!?”

“Washing each other?” Tomoe responded. She thought that was pretty obvious.

“Aren’t you two a little old for that?” Ran asked.

“Nope,” Ako replied, “This is a normal part of sisterly bonding.”  
  
“Well, alright, I guess.”

Ran was an only child, so it’s not like she had anything to compare this to.

“Anyway, Himari’s getting a bit impatient, so you two might want to hurry this up.”

“Got it. Come sit on my lap, Ako. I’ll get the suds off of us.”

Ran walked back to the hot spring, feeling just a little weirded out.

_____________________________________________________________________

It had been a great night. Tomoe had spent the last two hours cheering her little sister’s name and waving a pink glow stick at a Roselia concert. And now, after the concert was done, she had managed to whisk Ako away to a private spot so she could congradulate her. With a french kiss.

Even Ako and Tomoe know that it was something that went beyond the usual bonds of sisterly affection but… well, they were very close sisters, and if they enjoyed making out sometimes, so what? Still, both of them knew that society wouldn’t look at it that way, so they were always careful to make sure they were alone when they indulged in their bonding.

The whole thing had started a long time ago, when Ako and Tomoe were very young. One of their favorite games had been knight and dragon, where Tomoe was a cool and gallant knight who had to battle the equally cool but much more infernal dragon Akonasht. One day, Ako had decided to add a twist to the games where after defeating the dragon, Tomoe had to give her a kiss to transform her into a princess. That was how they gave each other their first kiss, a very pleasant one. Pleasant enough that kissing became a regular feature in their games, and even outside of them. Even after their parents had told them how odd it was, they had only been convinced to be a little more discrete.

Back then, their kisses were simple. Nothing more than a meeting of the lips. Tongues had only gotten involved later, when Ako had read something on the internet about ‘getting closer to the one you love’ and decided to try it out with her older sister.

Tomoe had resisted at first, but Ako had argued back. What was wrong with kissing? Sure, they would be sharing some germs, but they shared cups and forks at home anyway, so they were already doing that. And if french kissing was something you did with the one you love, then who on Earth would Ako be doing it with if not Tomoe? In the end, the elded Udagawa had never been the best at denying her younger sister. Her reward for her weakness had been a clumsy kiss that had been the most enjoyable of her life.

By now, Tomoe was too addicted to her little sister’s kisses to give them up willingly. Ako was just so enthusiastic, her tongue not leaving a single crevice of her older sister’s mouth unexplored.

“You’re really tasty, onee-chan.”

“You’re, uh, very nice too, Ako.”

The sisters were a little out of breath, but they didn’t wait long before tangling their tongues once more. Tangling their tongues in a sisterly way, Tomoe told herself, but deep down she knew that there was nothing sisterly about this. She was probably a bad older sister, doing things like this with an innocent girl like Ako. Or maybe Ako really was a demon, sent to tempt her into sin.

“I love you, onee-chan,” said Ako, resting her head against Tomoe’s chest.

“I love you too.”

There were many things Tomoe was unsure of, but that was something she’d never doubt. Even if she didn’t know exactly what sort of love it was, sometimes.

_____________________________________________________________________

Of all the sights Tomoe might expect to greet her in her room after band practice, the soft glow of candles lighting up rose petals and also her little sister wearing some  _very_ skimpy lingerie wasn’t one of them.

“Uh, Ako, not that it isn’t nice to see you or anything but… what are you doing?”

“Trying to seduce you, just like a succubus would,” Ako answered while making a stereotypical ‘sexy’ pose that had no doubt come from some anime or something. Tomoe wished she could say she found it more funny than sexy.

“Okay. Um. Any reason, sis?”

“Well, I was just thinking, sex - uh - making love is supposed to feel really good and, you know, I’m in high school now and it’s not rare for high schoolers to do that kind of thing.”

T omoe didn’t like where this was going. It’s not like she didn’t know her sister had those kinds of urges. There had been some times Ako had been a little forgetful about closing tabs in her browser. But she still thought of her little sister as an innocent angel that wouldn’t actually get involved in that kind of stuff.

“It may not be rare for a high schooler to have sex, but it’s not like it’s rare for a high schooler _not_ to have sex either. I’m a year older than you, and I haven’t done it yet,” Tomoe finally replied.

“Yeah but… when Ran and Moca took their relationship to the next level, they were only as old as I am now, weren’t they.”

“Well, sure, but they’d already been girlfriends for a while before that. I’m your sister. That’s very different.”

“Is it, though? I know that you should only have sex with people you love and trust, and that your first time is really special, but… You’re the person I love and trust the most in the whole wide world, so who else would I give my first time to? I know people don’t like it when sisters do that kind of thing, but it’s not like we could have a baby anyway.”

“That’s true, but are you really ready to deal with what people might say if they find out? I’m your older sister. It’s my job to protect you from the evils of the world. How could I do that if I’m the one laying my hands on you?”

“You laying your hands on me wouldn’t be evil, onee-chan. You’d be making me feel happy. And, I’ll do my best to make you feel happy too.”

Throughout the argument, Tomoe knew there was one thing she could say that would get her little sister to back off and give up on the absurd idea of them having sex: that she didn’t want to do it. That Ako simple didn’t interest her in that way, and she would prefer to just continue their relationship they had before.

But that would have been lying. And Tomoe wasn’t the best liar in the first place. She wished she was, so she could convince herself her love for her younger sister was purely platonic. Tomoe couldn’t, though. Nor could she lie to Ako.

“Okay, Ako. We can’t tell anyone about this, but if you really want me to be your first time… Well, I guess I can’t think of anyone more special than you to give my first time to either.”

Tomoe knew that she should have felt guilty, but it was so hard to when Ako was looking at her with such a bright smile. How could something that made her sister so happy be bad?

Ako wasted no time in giving her sister a deep kiss. Her hands unbuttoned Tomoe’s shirt, exposing her body, which wasn’t unusual for them, but time it would lead somewhere much further than a bath. Ako paused when her hands reached the back of her sister’s bra, waiting to see if the was really okay with this.

In response, Tomoe deepened their kiss and held her little sister tighter.

It didn’t take Ako long to get the bra off her sister. Tomoe’s pants and panties followed in short order. Despite the line being crossed, Tomoe didn’t flinch at all. She trusted her sister completely, with any part of her body. Still, as Ako’s hands approached her nethers, Tomoe pushed her off.

“Hang on, Ako, as your big sister, it’s my duty to put you first. That means making sure you get your pleasure first, too. Probably.”

“Alright, onee-chan. Then I’ll show you how to make me feel good.”

Ako took Tomoe’s hands and brought them to her core. Guiding her sister’s fingers into her folds and to her  sweet spot wasn’t so different from mastrubation. 

But somehow, the fact that it was her beloved onee-chan touching her made everything feel so much better. It wasn’t long before Tomoe took over, stimulating Ako’s pearl gently at first, then harder.

“Ah! Onee-chan, I love you so much!”

“I love you too Ako.”

The sisters kissed and embraced, Tomoe supporting Ako as she climaxed.

“Was that alright, little sis? Good enough for your first time?”

“It was the best, onee-chan. But now it’s my turn to show you the dark pleasures of sinful bonding.”

Tomoe let herself be pushed down. She prepared for a kiss, but instead, Ako got off of her. The elder Udagawa was confused until she felt two soft lips on her inner thigh. Tilting her head up, she could see her sister in between her legs.

“Uh, that’s a rather advanced technique you’re skipping to right there, isn’t it? Are you sure you don’t want to use fingers? That’s a dirty spot and I haven’t got a chance to wash yet.”

“Don’t worry. I learned in sex-ed that vaginas are self-cleaning and self-lubricating. The only thing I’m worried about is how much you’re enjoying it, so make sure to let out your sinfully cute and sexy moans, onee-chan.”

Once Ako’s tongue found its target, Tomoe couldn’t help but comply.

“Ako! I love you so much! Fu-fudge, that feels so good!”

Ako just continued to dive into her older sister, enjoying the fluids that spilled out. As Tomoe finally came, the younger Udagawa laid down beside her, resting her head on her older sister’s boobs and wrapping her arms around her.

“Did I do good, onee-chan? You were delicious, by the way.”

“Thanks, and yeah, you were really good, Ako. But since you got to taste me, it’s only fair that I get a taste of you too, right?”

“But didn’t you say that place was dirty? Id on’t want you to do anything you’re uncomfortable with.”

“I think I’d be uncomfortable if it was with anyone else, but if it’s you… well, when we were younger, I did have to help clean up when you wet the bed so this can’t be worse than that.”

“Onee-chan! That’s a really unsexy topic that’s really bad to bring up when we’re making love. You need to give me a bunch of forbidden pleasure to make up for it.”

“Sure, just give me a moment to catch my breath. I came right from Afterglow practice, after all.”

The sisters spend the rest of the night getting even closer than they had been before. Closer than society said they should be.

But as they woke up in each other’s arms the next morning, with the thought of having mornings like this for the rest of their lives, the sisters decided their happiness was more important.


End file.
